Inflight entertainment (IFE) systems have evolved significantly over the last 25 years. Prior to 1978, IFE systems consisted audio-only systems. In 1978, Bell and Howell (Avicom Division) introduced a group viewing video system based on VHS tapes. In 1988, Airvision introduced the first in-seat video system allowing passengers to choose between several channels of broadcast video. In 1997, Swissair installed the first interactive video on demand (VOD) system. Currently, several IFE systems provide VOD with full digital video disc-like controls.
In IFE systems, costs are highly dependent on the system's line replaceable units (LRUs). The term “LRU” is a term of art generally describing a complex component (e.g., “black box”) on an aircraft that is designed to be replaced quickly on the flight line or airport ramp area. LRUs are beneficial because they are generally self-contained units that can be rapidly swapped-out in the event that maintenance is required thus allowing the airplane to continue to operate with little down time. To be installed on an aircraft, an LRU hardware design configuration must be approved by the Federal Aviation Administration by means defined in Title 14 of the Code of Federal Regulations. LRUs of a particular hardware design configuration may have different software installed. An IFE system's installation costs, operating costs, maintenance costs and passenger comfort depend greatly on the size, form factor, number and weight of its LRUs, as well as the number of distinct LRUs deployed in a single aircraft and across an airline's entire fleet of aircraft.